Pub Date : 2020-08-26DOI: 10.1109/iWEM49354.2020.9237399
S. Yang, Xiu Yin Zhang
A dual-band dual-polarized array antenna based on filtering elements without using extra filtering circuit is proposed. The proposed array antenna consists of one low-band (LB) element with four filtering high-band (HB) elements around it. The two operating bands of the dual-band array antenna are respectively 1.7-2.7 GHz (LB) and 3.3-4.2 GHz (HB). Based on the filtering response of these elements, the isolation between LB and HB elements can be largely improved compared with normal antenna elements. The isolation between LB element and HB element is more than 25 dB. In addition, the radiation properties of the antenna elements operating in different bands are not distinctively affected by each other. These merits make the proposed dual-band array antenna suitable for massive multiband array applications.
{"title":"Dual-band Dual-Polarized Array Antenna Based on Filtering Elements","authors":"S. Yang, Xiu Yin Zhang","doi":"10.1109/iWEM49354.2020.9237399","DOIUrl":"https://doi.org/10.1109/iWEM49354.2020.9237399","url":null,"abstract":"A dual-band dual-polarized array antenna based on filtering elements without using extra filtering circuit is proposed. The proposed array antenna consists of one low-band (LB) element with four filtering high-band (HB) elements around it. The two operating bands of the dual-band array antenna are respectively 1.7-2.7 GHz (LB) and 3.3-4.2 GHz (HB). Based on the filtering response of these elements, the isolation between LB and HB elements can be largely improved compared with normal antenna elements. The isolation between LB element and HB element is more than 25 dB. In addition, the radiation properties of the antenna elements operating in different bands are not distinctively affected by each other. These merits make the proposed dual-band array antenna suitable for massive multiband array applications.","PeriodicalId":201518,"journal":{"name":"2020 International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM)","volume":"04 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128499330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study developed a novel shorted antenna with tuning slit for radio frequency identification (RFID) that mounted on a metallic plane. Conjugate matching of the resistance and inductive reactance of the antenna to the desired chip impedance can be performed by simply tuning the length of the slit etched on the patch. An Alien Higgs-4 chip (8.1-j149 Ω at 925 MHz) was connected to the short side strip of the feeding loop. The gap of 0.1 mm between the proposed antenna and the metallic plane can enhance the antenna gain from the reflection of the plane. After analysis and optimization of the tag antenna, fabricated tags mounted on a metallic plane had impedance bandwidths of 2.2%. In tests of an RFID reader with an effective isotropic radiated power (EIRP) of 4.0 W, the maximum read ranges for tag in an outdoor environment was 8.1 m.
{"title":"Shorted Patch Antenna with Tuning Slit for RFID Tag Mounted on Metallic Plane","authors":"Nguyen Minh Tan, Yi‐Fang Lin, Chien‐Hung Chen, Chun-Hsien Chang, Ying-Chih Tseng, Hua‐Ming Chen","doi":"10.1109/iWEM49354.2020.9237412","DOIUrl":"https://doi.org/10.1109/iWEM49354.2020.9237412","url":null,"abstract":"This study developed a novel shorted antenna with tuning slit for radio frequency identification (RFID) that mounted on a metallic plane. Conjugate matching of the resistance and inductive reactance of the antenna to the desired chip impedance can be performed by simply tuning the length of the slit etched on the patch. An Alien Higgs-4 chip (8.1-j149 Ω at 925 MHz) was connected to the short side strip of the feeding loop. The gap of 0.1 mm between the proposed antenna and the metallic plane can enhance the antenna gain from the reflection of the plane. After analysis and optimization of the tag antenna, fabricated tags mounted on a metallic plane had impedance bandwidths of 2.2%. In tests of an RFID reader with an effective isotropic radiated power (EIRP) of 4.0 W, the maximum read ranges for tag in an outdoor environment was 8.1 m.","PeriodicalId":201518,"journal":{"name":"2020 International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127222499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-26DOI: 10.1109/iWEM49354.2020.9237394
Tso-Hua Lin, R. Hwang
This work presents a beam-steerable antenna that is based on the holographic theory. The fixed-pattern hologram is made of metal strips coat on a polymethyl methacrylate (PMMA) slab. A surface-wave launcher generate the reference wave; in particular, with the beam-steering capability. Such an antenna can steer its main beam from −19° to +19° with the directivity varying between 13.85 and 16.93 dBi; the operating frequency ranges from 3.4 GHz to 3.6 GHz.
{"title":"A Beam-steerable Holographic Antenna","authors":"Tso-Hua Lin, R. Hwang","doi":"10.1109/iWEM49354.2020.9237394","DOIUrl":"https://doi.org/10.1109/iWEM49354.2020.9237394","url":null,"abstract":"This work presents a beam-steerable antenna that is based on the holographic theory. The fixed-pattern hologram is made of metal strips coat on a polymethyl methacrylate (PMMA) slab. A surface-wave launcher generate the reference wave; in particular, with the beam-steering capability. Such an antenna can steer its main beam from −19° to +19° with the directivity varying between 13.85 and 16.93 dBi; the operating frequency ranges from 3.4 GHz to 3.6 GHz.","PeriodicalId":201518,"journal":{"name":"2020 International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114157938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-26DOI: 10.1109/iWEM49354.2020.9237431
Ching-Lieh Li, He-Di Liu, Wei‐Hsuan Tang, Yu-Jen Chi
This paper investigates the design of a pixelated electrode plates for capacitive wireless charging suited for mobile phone with metal shell. The study focuses on solving the problem that the effective coupling area (ECA) is relatively small when the secondary electrode plate is shifted in X direction and/or in Y direction and the variation of ECA is kept low. For the first time, the novel concept of “vacant” pixel is introduced into the capacitive charging plate, via which the above mentioned problem of small ECA, caused by the placement offset of the secondary electrode plate, is overcome. A tristate discrete particle swarm optimization (TDPSO) scheme is applied to optimize the pixel distribution of both pixelated positive and negative electrode plates, and the vacant pixel distribution in between. Via the global search scheme TDPSO we are able to determine the shapes of positive and negative electrodes for both the primary side (charging board) and the secondary side (charged board, such as a mobile phone).
{"title":"Innovative Design of Pixelated Electrode Plates for Capacitive Wireless Charging","authors":"Ching-Lieh Li, He-Di Liu, Wei‐Hsuan Tang, Yu-Jen Chi","doi":"10.1109/iWEM49354.2020.9237431","DOIUrl":"https://doi.org/10.1109/iWEM49354.2020.9237431","url":null,"abstract":"This paper investigates the design of a pixelated electrode plates for capacitive wireless charging suited for mobile phone with metal shell. The study focuses on solving the problem that the effective coupling area (ECA) is relatively small when the secondary electrode plate is shifted in X direction and/or in Y direction and the variation of ECA is kept low. For the first time, the novel concept of “vacant” pixel is introduced into the capacitive charging plate, via which the above mentioned problem of small ECA, caused by the placement offset of the secondary electrode plate, is overcome. A tristate discrete particle swarm optimization (TDPSO) scheme is applied to optimize the pixel distribution of both pixelated positive and negative electrode plates, and the vacant pixel distribution in between. Via the global search scheme TDPSO we are able to determine the shapes of positive and negative electrodes for both the primary side (charging board) and the secondary side (charged board, such as a mobile phone).","PeriodicalId":201518,"journal":{"name":"2020 International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129628105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-26DOI: 10.1109/iWEM49354.2020.9237408
Yuting Zhao, Yingsong Li, X. Liu
In this paper, a single-layer wideband absorber with wide angular coverage is presented. The resistive surface is realized by a periodic array of I-shaped capacitive patterns with chip resistors. By introducing the capacitive patterns, the distance between metal ground and resistive surface with air space is reduced to 1/5 λ @10 GHz. A 10-dB absorption bandwidth from 5.5 GHz to 14.5 GHz has been observed in simulation under normal incidence of TE polarization. This structure also exhibits an angular stability up to 30° with a wide absorption band of at least 90% absorptivity from 4.8 GHz to 14.5 GHz. The fabricated design shows good agreement with the simulation.
{"title":"A Low-Profile Wideband Absorber Using Capacitive Surface","authors":"Yuting Zhao, Yingsong Li, X. Liu","doi":"10.1109/iWEM49354.2020.9237408","DOIUrl":"https://doi.org/10.1109/iWEM49354.2020.9237408","url":null,"abstract":"In this paper, a single-layer wideband absorber with wide angular coverage is presented. The resistive surface is realized by a periodic array of I-shaped capacitive patterns with chip resistors. By introducing the capacitive patterns, the distance between metal ground and resistive surface with air space is reduced to 1/5 λ @10 GHz. A 10-dB absorption bandwidth from 5.5 GHz to 14.5 GHz has been observed in simulation under normal incidence of TE polarization. This structure also exhibits an angular stability up to 30° with a wide absorption band of at least 90% absorptivity from 4.8 GHz to 14.5 GHz. The fabricated design shows good agreement with the simulation.","PeriodicalId":201518,"journal":{"name":"2020 International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129924698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-26DOI: 10.1109/iWEM49354.2020.9237451
Chung-En Yu, Chin-Lung Yang
A neural network-based method for multi-layer permittivity measurement is proposed in this paper. This method uses the multiple-square concentric complementary split-ring resonator (CSRR) to take multiple non-identical resonance frequency measurement, and a scalable, iterative neural network approach is applied to estimate for dielectric property measurement. Instead of the tedious development and establishment of analytic formulas, neural network engine solver can simplify this step and still have acceptable accuracy. The dual-layer MUTs measurement had an average error of 8.78% for ε1 and an average error of 8.9% for ε2. It can be extended to the measurement of more than two layers substrate.
{"title":"Multi-layer Permittivity Measurement Based on Complementary Split-Ring Resonator and Neural Networks","authors":"Chung-En Yu, Chin-Lung Yang","doi":"10.1109/iWEM49354.2020.9237451","DOIUrl":"https://doi.org/10.1109/iWEM49354.2020.9237451","url":null,"abstract":"A neural network-based method for multi-layer permittivity measurement is proposed in this paper. This method uses the multiple-square concentric complementary split-ring resonator (CSRR) to take multiple non-identical resonance frequency measurement, and a scalable, iterative neural network approach is applied to estimate for dielectric property measurement. Instead of the tedious development and establishment of analytic formulas, neural network engine solver can simplify this step and still have acceptable accuracy. The dual-layer MUTs measurement had an average error of 8.78% for ε1 and an average error of 8.9% for ε2. It can be extended to the measurement of more than two layers substrate.","PeriodicalId":201518,"journal":{"name":"2020 International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM)","volume":"33 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132334779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-26DOI: 10.1109/iWEM49354.2020.9237417
Chi-Yu Yang, T. Ma, Huy Nam Chu, Yi-Lin Tsai
This paper briefly reviews the recent development on self-oscillating circularly-polarized active integrated antennas (CPAIAs), including the advance in antenna design as well as the advance in measuring facilities. CPAIA is a rare topic drawn unreasonably little attention in the literature. We believe it is most likely due to the lack of an easy and low-cost measuring facility for experimental validation, particularly the axial ratio. Recently, we tackle this issue and develop a low-cost polarization sensing system. With the powerful portable equipment, CPAIA designs are no longer a difficult task and a few examples are given in this discussion.
{"title":"Recent Development on Circularly-Polarized Self-oscillating Active-Integrated Antennas and Its Measuring System","authors":"Chi-Yu Yang, T. Ma, Huy Nam Chu, Yi-Lin Tsai","doi":"10.1109/iWEM49354.2020.9237417","DOIUrl":"https://doi.org/10.1109/iWEM49354.2020.9237417","url":null,"abstract":"This paper briefly reviews the recent development on self-oscillating circularly-polarized active integrated antennas (CPAIAs), including the advance in antenna design as well as the advance in measuring facilities. CPAIA is a rare topic drawn unreasonably little attention in the literature. We believe it is most likely due to the lack of an easy and low-cost measuring facility for experimental validation, particularly the axial ratio. Recently, we tackle this issue and develop a low-cost polarization sensing system. With the powerful portable equipment, CPAIA designs are no longer a difficult task and a few examples are given in this discussion.","PeriodicalId":201518,"journal":{"name":"2020 International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123841723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-26DOI: 10.1109/iWEM49354.2020.9237410
Shu-Chuan Chen, L. Chou, Chung-I. G. Hsu, Sheng-Min Li
A sub-6-GHz multi-input multi-output (MIMO) slot antenna system was proposed in this study, where each antenna element was constructed using a slot structure. To effectively use the available space in a tablet and maximize the screen, we have deployed the MIMO antenna system on the left side-edge frame of the tablet. The MIMO antenna system consists of two identical dual-slot-antenna units that are separated by 10 mm. The two closely spaced slot antennas in the same dual-slot-antenna unit are arranged asymmetrically mirrored of each other with respect to the system ground plane. The isolation between its two slot antennas can be enhanced by 5 dB to meet the design requirement by using an ungrounded full-wavelength microstrip resonator.
{"title":"Compact Sub-6-GHz MIMO Slot Antenna System","authors":"Shu-Chuan Chen, L. Chou, Chung-I. G. Hsu, Sheng-Min Li","doi":"10.1109/iWEM49354.2020.9237410","DOIUrl":"https://doi.org/10.1109/iWEM49354.2020.9237410","url":null,"abstract":"A sub-6-GHz multi-input multi-output (MIMO) slot antenna system was proposed in this study, where each antenna element was constructed using a slot structure. To effectively use the available space in a tablet and maximize the screen, we have deployed the MIMO antenna system on the left side-edge frame of the tablet. The MIMO antenna system consists of two identical dual-slot-antenna units that are separated by 10 mm. The two closely spaced slot antennas in the same dual-slot-antenna unit are arranged asymmetrically mirrored of each other with respect to the system ground plane. The isolation between its two slot antennas can be enhanced by 5 dB to meet the design requirement by using an ungrounded full-wavelength microstrip resonator.","PeriodicalId":201518,"journal":{"name":"2020 International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM)","volume":"129 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116248464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-26DOI: 10.1109/iWEM49354.2020.9237415
Ho‐Chang Lee, S. Jang, Yang-Hsuan Fan, Fu-Sheng Chou, Yu-Shen Liao, M. Juang
This letter studies the RF performance of wideband divide-by-2 injection-locked frequency dividers (ILFDs) with various inductor layouts in the 0.18 µm CMOS process. The ILFDs use an inductor composite in shunt with parasitic capacitors as the resonator, and they also use capacitive cross-coupled pairs to generate negative resistance for start-up oscillation. The gate biases of capacitive cross-coupled pairs are used to tune the free-running ILFD oscillation frequency. The first designed ILFD uses two octagonal inductors, the inductors in other two ILFDs use a twisted configuration and the ILFDs have low EM radiation level and less sensitive to received EM noise. These ILFDs have wide locking range because no varactors is in shunt with injection FETs.
{"title":"Divide-by-2 Injection-Locked Frequency Dividers with Twisted Inductors","authors":"Ho‐Chang Lee, S. Jang, Yang-Hsuan Fan, Fu-Sheng Chou, Yu-Shen Liao, M. Juang","doi":"10.1109/iWEM49354.2020.9237415","DOIUrl":"https://doi.org/10.1109/iWEM49354.2020.9237415","url":null,"abstract":"This letter studies the RF performance of wideband divide-by-2 injection-locked frequency dividers (ILFDs) with various inductor layouts in the 0.18 µm CMOS process. The ILFDs use an inductor composite in shunt with parasitic capacitors as the resonator, and they also use capacitive cross-coupled pairs to generate negative resistance for start-up oscillation. The gate biases of capacitive cross-coupled pairs are used to tune the free-running ILFD oscillation frequency. The first designed ILFD uses two octagonal inductors, the inductors in other two ILFDs use a twisted configuration and the ILFDs have low EM radiation level and less sensitive to received EM noise. These ILFDs have wide locking range because no varactors is in shunt with injection FETs.","PeriodicalId":201518,"journal":{"name":"2020 International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM)","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128545999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-26DOI: 10.1109/iWEM49354.2020.9237392
Michael Chang
This paper provides supply-induced sensitivity methodology to solve RF integrated transmitter IP design challenge in co-design chip, package and system. Supply noise induced error vector magnitude (EVM) degradation is one of the major sources of SNR degradation in RFIC systems. In this paper, the methodology for RF front-end IP is developed using the frequency-dependent uncertainties transfer function and relationship between induced uncertainty and EVM degradation. The analysis results are also well correlated with constellation diagram which is a representation of a signal modulated by a digital modulation scheme designed in highly-integrated RF transceiver for WLAN applications. The proposed methodology provides uncertainty-aware frequency-dependent PDN target impedance modeling. The goal during is to provide adequate performance for cost-effective and system solution at early design stage and achieving on system-level success.
{"title":"EVM-aware PDN Target Impedance for Integrated RF System","authors":"Michael Chang","doi":"10.1109/iWEM49354.2020.9237392","DOIUrl":"https://doi.org/10.1109/iWEM49354.2020.9237392","url":null,"abstract":"This paper provides supply-induced sensitivity methodology to solve RF integrated transmitter IP design challenge in co-design chip, package and system. Supply noise induced error vector magnitude (EVM) degradation is one of the major sources of SNR degradation in RFIC systems. In this paper, the methodology for RF front-end IP is developed using the frequency-dependent uncertainties transfer function and relationship between induced uncertainty and EVM degradation. The analysis results are also well correlated with constellation diagram which is a representation of a signal modulated by a digital modulation scheme designed in highly-integrated RF transceiver for WLAN applications. The proposed methodology provides uncertainty-aware frequency-dependent PDN target impedance modeling. The goal during is to provide adequate performance for cost-effective and system solution at early design stage and achieving on system-level success.","PeriodicalId":201518,"journal":{"name":"2020 International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM)","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130863468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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